Damping material is basically simply a big, heavy sticker.
You cut it to size, and apply it to panels to add mass to them.
This shifts their resonant frequency downward, and makes so the now-lower-in-frequency vibrations take more energy to get going in the first place.
Some damping materials may actually help block sound, such as road noise, from entering the cabin... but that requires a full coverage, without any exposed-metal spots remaining.
So...
It's safe to say, if you have vibrating metal (the sheet metal itself actually vibrating)... that's the noise that damping material such as this will help damp.
Certain damping products can block noise, a full coverage of any damping product (without leaving exposed metal) can at least help block road noise in just about any case.
If you have other things vibrating... loose bolts, wires slapping metal, devices like seat belt retractors or license plates or polyurethane bumpers with foam cores... if those are buzzing, damping material won't help those at all.
Hope that helps! //content.invisioncic.com/y282845/emoticons/cool.gif.3bcaf8f141236c00f8044d07150e34f7.gif
